What Factors Determine the Performance of a BJT Differential Amplifier?

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The discussion focuses on analyzing the performance factors of a BJT differential amplifier, specifically addressing differential input resistance, differential voltage gain, single-ended voltage gain, common-mode voltage gain, common-mode rejection ratio (CMRR), common-mode input resistance, and single-ended output resistance. The user proposes a formula for calculating differential input resistance, suggesting it is the sum of Rib and R3. There is uncertainty about the calculation of Rib, which involves parameters like ie and re. The conversation hints that this technical question may be better suited for a specialized forum like electrical.stackexchange. Overall, the thread emphasizes the complexity of analyzing BJT differential amplifiers and the need for precise calculations.
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Homework Statement


diff amp.PNG


Analyse the circuit to provide predictions for (a) the differential input resistance, (b) differential voltage gain, (c) single-ended voltage gain, (d) common-mode voltage gain, (e) common-mode rejection ratio (CMRR) in dB, (f) common-mode input resistance and (g) the single-ended output resistance. The common-mode gain may be calculated using the output admittance (hOE) in Fig. 6 in the CA3086 data sheet. [ro = 1 / hOE].

Homework Equations

The Attempt at a Solution



For a) is the differential input resistance just
Rid = Rib + R3, where Rib is the resistance looking into the base

Rib = ie(re + R6/2)/ib
 
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that is a question indeed !...but I think this might not be the forum for this kind of question...try in electrical.stackexchange
 

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